In recent years, attention has been directed toward a wireless network using a low-power-consumption wireless device, such as WPAN (Wireless Personal Area Network) typified by the IEEE (Institute of Electrical and Electronics Engineers) 802.15 standard and a sensor network.
For example, Patent Literature (PTL) 1 discloses a technique for preventing collision between packets. According to this technique, a connector corresponding to a controller generates a reference clock and reference timing on the basis of transmitted data. Accordingly, a TDMA slot used by the controller can be prevented from overlapping with a TDMA slot used by another controller. As a result, it is possible to prevent the collision between packets, which is caused when the number of communication terminals connected to the controller increases.